FIG. 1 is a perspective view of prior art stator 1 for a torque converter. It is known to fabricate a stator for a torque converter using casting of metals, such as aluminum, or molding of materials such as phenolic resin. In particular, these techniques are used to form blades 2 for a stator as a single unit. Typically, stator blades 2, core ring 3, and portions of stator body 4 are formed as a single unit or piece. Unfortunately, casting can be a relatively costly process. Also, cast stators typically require additional machining to accept other components, such as a one-way clutch, side plates, or a snap ring. Typically, dies used to fabricate stators are of a radial pull configuration or an axial pull configuration. Due to cost considerations, the axial pull configuration is more commonly used. For example, for radial pull stators, the core ring cannot be included in the cast or mold. Therefore, a separate core ring, typically steel, must be wrapped around the stator outside diameter and welded into place.
Improved hydrodynamic performance can be achieved by various configurations of the blades in a stator. For example, the shape of the blades in the stator influences the efficiency with which the stator transfers fluid from the turbine to the pump. In many cases, the blades must significantly redirect the flow. The inlet angle of the blades measures the orientation of the nose of the blade (the end of the blade on the turbine side of the stator). The efficiency of the fluid transfer in the stator is a function of the alignment of the inlet angle with the direction of fluid flow from the turbine. That is, the closer the alignment, the better the efficiency. Unfortunately, the use of dies limits the configurations possible among the blades formed by the die. Specifically, the blades and other components formed in the die must be shaped and aligned so that at all points, the surface features of the die have an unrestricted removal path. For example, for an axial pull configuration, the die is pulled away in axial directions 5 and 6. Therefore, there can be no undercutting or overlapping of the blades and components that would interfere with removal of the die in directions 5 and 6. For example, the blades cannot circumferentially overlap. That is, an axial plane (not shown) passing through axis 7 cannot intersect adjacent blades. Regarding the inlet angle noted above, an optimal inlet angle for applications requiring increased torque ratio typically requires that the nose of the blade be significantly curved with respect to the remainder of the blade body. Unfortunately, such curvature creates overlaps that are untenable for an axial pull die. Therefore, for an axial pull die, the nose of the blades must be undesirably “flattened” to avoid axial overlaps, undesirably limiting the inlet angle possible for the blades. Due to inherent constraints in the casting process, cast blades must be made with a minimum thickness. Unfortunately, this minimum thickness is sometimes detrimental to the performance of the stator.
Thus, there is a long-felt need for a stator with blades configured for improved hydrodynamic performance. There also is a long-felt need for a stator that can be fabricated using processes that are simpler and more cost-effective, and materials that are more inexpensive than are associated with casting and molding operations.